1. Field of the Invention
This invention relates to treating subsurface layers and treated subsurface layers, adjacent the surface of the earth, to either control movement of subsurface water or build strength of the subsurface layers, or both. More particularly, this invention relates to improving the subgrade; as for buildings, road beds, or the like.
2. Description of the Prior Art
The prior art is replete with a wide variety of materials that have been employed to stabilize soils, or improve subgrades in the subsurface layers adjacent the surface of the earth for a variety of purposes. The applications have been as varied as improving subgrades for streets, runways, railroads, dewatering projects and more recently, improving the slopes to prevent failure thereof. Of course, pretreating building sites for improving the strengths and water flow characteristics of soils has long been a problem plaguing the civil engineer and the architectural engineer. The problems have been varied and the techniques have been varied to try to overcome them. Lime slurries have been worked into the top layers; for example, the top several to as much as fourteen or more inches in depth to improve and stabilize soils, or subgrades. Other more exotic and expensive treatment, such as injection of furfural alcohols, that have been found to work in subterranean formations, have been tried. Such exotic treatments have proven too expensive and not altogether successful because of the lack of metamorphosed rock in the subsurface layers adjacent the surface of the earth. Expressed otherwise, these exotic treatments were infeasible and engineeringly inoperable because of the numerous small cracks, crevices and the like that traverse through soil and the soils were composed largely of sedimentary materials, amorphous materials, humous matter, non crystallographic materials and the like, that could not be considered as were the subterranean formation.
Preliminary work has indicated that a stabilizing method and the resulting stabilized layers adjacent the surface of the earth should provide one or more of the following features not heretofore provided by the prior art.
1. The injected materials should undergo a reaction with time to produce water-insoluble materials that will block the flow of water.
2. The injected materials should react with time to form materials that will strengthen the soil, or subsurface layers, into which they are injected.
3. The injected material should be in a slurry form so as to traverse along minute fissures, cracks and the like to obtain widespread stabilization effects.
4. The method should enable stabilizing railroad subgrades by injecting into the roadbed to control the flow of water and strengthen the subgrade.
5. The method should enable injection of a slurry into deep ballast pockets on a roadbed to displace the water, prevent re-entry of water and build to a strength greater than that initially occupying the ballast pockets.
6. The method should be useful in stabilizing slopes against slides, shear failure, slough offs, and the like.
7. The method should be amenable to a variety of injection techniques, depending upon the extent and grade of the slopes or the like.
8. The injection method should be useful for dewatering and cutting off subsurface flow of water, as into an excavation for a building, highway, and the like.
9. The method should be useful for remedial work around a home to stabilize the moisture content around the home foundations to prevent alternate drying and subsequent rewetting with attendant expansion and contraction of the soils so there will be less damage, such as cracking of the walls, foundation and the like.
10. The method should be usable as a thick grout to allow pumping through a hole to raise a slab for cosmetic effects, relevelling and the like.
It can be seen that the prior art has been deficient in providing an economical process that has one or more of the foregoing features.